In the prior art, a unicast communication system uses a point-to-point propagation mode, and has the advantages that a server responds to a request of a client in time and can send different data in response to different requests of clients, and personalized service can be easily realized. With the rise of data services and improvement of the data rate, currently, most unicast communication systems mainly for transmission of a large amount of data traffic adopt an AMC (Adaptive modulation and coding, adaptive modulation and coding) and HARQ (Hybrid automatic repeat request, hybrid automatic repeat request) mechanism, so as to improve the transmission efficiency by adapting to channel characteristics.
However, in order to more accurately track the channel characteristics, a feedback overhead of the system is increased, which restricts the throughput of the system, and especially when the channel is unstable, a feedback grain may bring a heavy burden to the system. As a result, the system cannot efficiently support large-scale data transmission.